Oolong, or Wu Long as it is also know, is a semi-oxidized tea that ranges between a green and a black tea depending on the percentage of oxidation. The caffeine content can vary widely but as a general rule, oolongs have more caffeine that whites/greens and less that blacks. Oolongs are rich in antioxidants such as theaflavin, tea catechin and polysaccharides. It is widely consumed to aid in lowering cholesterol, improve artery function, and help stabilize blood sugar, aid in weight loss and control.